During an HIV-infection there is a loss of T cells with production and repopulation of the lymphoid system with new T cells. With age there the rate of loss in adults seems to be similar and independent of age. However, the rate of production of new functional T cells is age related and it occurs at a slower rate the older patient. Younger HIV-infected patients can experience extended periods where their CD4+ cell level remains in the normal range and they are free of opportunistic infections. In the older patient there is a decline in the time between infection and the development of AIDS and a decline in the time of survival after the development of AIDS. One way of extending survival would be to slow the rate of cell loss since we do not have the ability to counter the effects of thymic involution. The mechanisms accounting for the T cell loss are thought to be linked to an autoimmune process and/or an apoptotic event during cellular activation. Both mechanisms play a role. The immune response to HIV involves both anti-HIV antibody as well as anti-HLA antibody. Methods involving the insertion of multiple gene copies into T cells allows the cell to resist the apoptotic results of activation and infection. It does not inhibit infection but does allow the cells to surviv